Regulator



- .Jan. 3, 1928.

Original Filed Jan.7. 1926 REGULATOR -2 Sheets-Sheet 1 wwwww Fig. 0 I5 by M24 W Z2 Z5 Z6 Inventor: Albert W. Hull,

His Attorney.

Jan. 3.192s, 1,655,389

A. w. Huu.

REGULATOR -Origiuai Filed Jan.'7. 1926 2 Sheets-Sheet 2 Fig. 4.

Inventor: Albert W Hui I,

by M His Attorneg.

Patented Jan. 3, 1928.

UNITED STATES PATENT OFFICE.

ALBERTW. HULL, OF SCHENEC'IADY, NEW YORK, ABBIGNOB '10 GENERAL ELECTRIC GOHPANY, A CORPORATION OF NEW YOR REGULATOR.

Application filed January 7, 1926, Serial No. 79,888. Renewed fictober 27, 1927.

My invention relates to arrangements for regu ating the operation of electric machines or circuits, and has for its principal object the provision of an improved regulator that does not involve the use of moving parts and is both sensitive reliable in its opera tion.

Various arrangements have been proposed and used in the past for regulating the voltage or other electrical condition of an electric machine or circuit. Many of these arrangements involve the use oi moving contacts and are incapable of producing the fine degree of regulation required for many w practical purposes, or the continuous reliable operation required in large central stations.

In accordance with my invention, these dif ficulties are avoided or minimized by a regulating system comprising an electron dis- 29 charge device which operates without appreciable time delay and without moving parts to prevent variation in the voltage or other electrical condition to be regulated.

, My invention will be better understood from the following description when considered in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

Referring to the drawing, Fig. 1 shows diagrammatically the invention as utilized in a voltage regulating system comprising a Wheatstone bridge type of pick-up device; Fig 2 shows diagrammatically a system comprising means for amplifying the effect of the pick-up device; and Figs. 3 and 4- v diagrammatically systems comprising rent types of picl -up devices.

1 shows a generator 1 that is connected to a load circuit 2 through slip rings 3 is provided with a field winding 4 adapted to be supplied with current from a suitable source through resistors 5 and 6.

A voltage responsive or Wheatstone bridge device comprising a pair of elements, shown 1 respectively as a ballast lamp 7 connected to the load circuit 2 in series with a resistor 8 and a ballast lamp 9 connected to the load circuit in series with a resistor 16, is pro- "vided for producing a voltage having its sense and magnitude determined by variations in the load circuit voltage. It will be observed that the lamp 7 and resistor 8 and the lamp 9 and resistor 10 are connected to A transformer 151 s provided with a primary winding 16 which is connected to the load circuit 2 and is inductively related to sccondary windings l7 and 18 connected at points intermediate their terminals to the resistors 5 and 6 through leads 19 and 20.

An electron discharge device 21 comprising pairs of anodes 22 and 23 connected in reverse order to the terminals of secondary circuits 1? and 18, grids 25 to 28 connected to the terminals of secondary circuit 13, and a cathode 29 connected both to the generator field circuit at the junction between resistors 5 and 6 and to the secondary circuit 13 at a point intermediate its ends is provided for regulating the current of winding 4 in response to variation in the load circuit voltage.

The device 21 is preferably a gas-containing device of the thyratron t pe. The cathode 29 may be an electrica ly heated filament, or a mercury pool, maintained in an electron-emitting condition by a small current to a separate anode or pair of anodes not shown in the figure.

he manner in which regulation of the load circuit voltage is effected will be readily understood if it be assumed that the filaments of lamps 7 and 9 are made of tungsten or the like and the resistors 8 and 10 are constructed of amaterial having a low temperature coefiicient of resistance.

Under these conditions, the currents transmitted through the lamps 7 and 9 will vary ap roximately as the square roots of the v0 tages applied at the lamp terminals while the currents through the resistors 8 and 10 will vary as the first power of the volta es applied to the resistor terminals, and tie resistances of the lamps and resistors may be so balanced or proportioned that no potential difference exists between the juncture of lamp 7 and resistor 8 and that of lamp 9 and resistor 10 when the load circuit voltage is at its normal value. Variation from the normal value of the load circuit voltage, however, produces a difference of. potential between the juncture points, this potential volta e when the anodes 22 are positive,

and t e generator field current is reduced due to the counter electromotive force produced in the field circuit by the current transmitted to the resistor 6 through the device 21 and the secondary circuit 17. Since the anodes 23 are negatively charged during this period, no current is transmitted to the resistor 5 through device 21. Upon a decrease in the load circuit voltage below its normal value, however, the potential applied to the grids 25 to 28 is reversed. lhe grids 27 and 28 are positively charged during the half cycle when the anodes 23 are positive,

a current flows through the device 21 and conductor 20, and an E. M. F. is introduced into the portion 5 of the field circuit which produces an increase in the generator excitation and voltage. Any departure of the generator or load circuit voltage from its normal value thus instantaneously brings lnto operation a force tending to restore it to its normal value.

Fig. 2 shows a re lating system wherein a thermionic ampli er 30 is connected between the electron discharge device 21 and the Wheatstone bridge device and wherein the current of the device 21 is utilized to regulate the output of an exciter 31 which supplies current to the generator field windng 4. In this system the transformer winding 13 is connected between the cathode and grid of the amplifier 30, the cathode and anode of the amplifier 30 are interconnecte throu h the armature of the exciter 31 which supplies current to the primary circuit 32 of a transformer 33, and potential is applied to the grids 25 to 28 through the secondary circuit 34 of the transformer 33. The amllfier 30 thus functions to amplify the efec-t produced by variation in the load circult voltage. It will be readily understood that this amplified effect may be utilized to regulate the generator voltage either directly or through the emitter which suppl es the generator field current. The operatlon of the system shown by Fig. 2 is simiand will be readilyunderstood without ther explanation.

' Fig. 3 shows a system wherein variation in the load circuit voltage is utilized to conto those of the mercury va or arc trol the current supplied to the generator field winding 4 through a gas filled, device 35 having operating charactertistics similar device 21 shown in Figs. 1 and 2. 'T e device 35 comprises anodes 36 and 37 which are connected to opposite terminals of a secondary windhea set load circuit 2. It Will be observed that the cathodes 51 and 52 are connected in series to a secondary winding 53 of the transformer 39; that the cathode 44' of the gas-containing device 35 is connected to the secondary winding 53 at a point intermediate its ends; that the anode 49 is connected directly to the rid 41 and through resistor 43 to the ano e 36; and that the anode 50 is connected directly to the grid 40 and through resistor 42 to the anode 37.

A switch 54 is provided for connecting the generator field winding 4 either to direct current supply means 55or between the cathode 44 of device 35 and a, point intermediate the ends of the secondary winding 38. It will be apparent that the secondary voltages of the transformers 39 and 45 are proportional in value to the armature voltage of the generator.

Assuming the machine 1 to be driven at its normal speed, its operation as a generator may be initiated by operating the switch 54 to connect the field winding 4 to the direct current sup 1y line 55 thus ensuring that the machine v0 tage immediately attains its normal value. The switch 54 may then be operated to connect the field winding 4 to the d transformer 39 through the device 35.

With this connection, rectified current is supplied from the secondary winding 38 through the device 35 to the field winding 4. So long as the voltage of the machine 1 is normal, iust enough current to maintain this voltage issupplied to the field winding 4.

If the machine voltage exceeds its normal value, the volta e. of the secondary circuit 53 is increased. an currents of increased value are transmitted alternately to resistors 42 and 43 through circuits one of which comprises device 46, resistor 43, the lower portion of winding 38, the field winding 4, and the upper portion of the secondary winding 53 and the other of which comprises device 47 resistor 42, the upper portion of winding 38, fie'ldwindin 4, and the lower portion of secondary winding 53. As the currents transmitted through the resistors 42 and 43 increase in value, the potentials of grids 40 and 41 became more negative with respect to those of the anodes 37 and 36 and when a definite negative value is reached the device 35 becomes non-conducting, thus interrupting the supply of current to the field windthe devices 67 and 68 Ti the machine voltage decreases below its normal value,

the currents transmitted through resistors 42 and 43 are reduced, the potentials of the grids and 41 become more positive with respect to those of the anodes 36 and 37, current is supplied to the field winding 4 from the secondary circuit 38, and the voltage of the load circuit 2 is increased.

Fig. 4 shows the invention as utilized to regulate the voltage of a direct current machine comprising armature and field windings 56 and 57 which are interconnected through an impedance device SllOWll as a resister 58. The machine 55 may also be provided with slip rings 59 and 60 to afiord an alternating current source which is con nected to a gas-containing device 61 through a transformer 62 and to a pair of transformers 63 and 64 which are provided for heating the cathodes 65 and 66 of electron discharge devices 67 and 68 respectively. The gas-containing device 61 comprises anodes 69 connected to opposite terminals of the secondary circuit I ode 70 connected to the anodes 69 through resistor 58 and opposite halves of the secondary. circuit of transformer 62, grids 71 which are connected to the cathode 70 through the anode 72 and cathode 66 or" device 68, and an excitation electrode 73 which is connected to the armature winding 56 through a resistor 74.

The pick-up device of the system shown by Fig. 4 com rises magnetically controlled devices 67 an 68 which are connected in cascade to the load circuit 75 of the direct current machine 55. It will be observed that are provided with magnetic field control coils 76 and 77 that the cathode 66 and anode 72 of device 68 are interconnected through the armature windin 56 and a resistor 78, that the magnetic fiel control coil of device 67 is connected to the load circuit 75 through a resistor 79 and that the cathode 65 and anode 80 ofdevice 67 are interconnected through the armature windin 56 and magnetic field coil 7 7 of device 68.

TVi h these connections, variations in the load circuit voltage are amplified by the devices 67 and 68 and these amplified variations are applied to the grids 71 of the device 61 in a manner to control its conductivity. If the machine 55 is operating at normal voltage, the resistor 58 tends to transmit just enough current to the field winding 57 to maintain this voltage. If the voltage of the machine increases, however, the current of the magnetic field windings 76 is increased, less current is supplied to the magnetic field I duct of transformer 62. a cathh winding 77, the potential drop of device 68 and hence the potential difi'erence between grids and cathode of device 61 is decreased to the point where device 61 ceases to concurrent, the added electromotive force produced in the resistor 58 by current transmitted through the device 61 decreases, and the excitation and voltage of the machine 56 is reduced.

If the machine voltage decreases below its normal value, the current of the magnetic field winding 76 is reduced, more current is is supplied to the magnetic field winding 77, the drop of device 68 is increased, the conductivity of device 61 and hence the electromotive force produced in the resistor 58 by current transmitted through device 61 is resorted, more current is supplied to the field winding 57 and the machine voltage is increased. As in all the modifications previously described, any slight departure of the machine voltage from its normal value thus immediately brings into operation a force tending to restore it to its normal value.

The embodiments 01E the invention illustrated and described herein have been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the invention issusceptible of eing modified to meet the different condltions encountered in its use and I therefore aimto cover by the appended claims all modifications within the true spirit and scope of my invention.

What T claim as new and desire to secure by Letters Patent of the United States is:

1. The combination of an electric machine comprising field and load circuits, a plural ity of control devices connected In said field circuit, an electron discharge device comprising grids interposcd between a cathode connected to said field circuit at a puncture between said control devices and anodes connected to the terminals of said control devices, and means connected between said cathode and grids for varying the potentials of said grids in response to variation in an electrical condition of said load circuit.

2. The combination of a load circuit, means comprising a field circuit and a resistor connected in series with said field circuit for controlling an electrical condition of said load circuit, an electron discharge device provided with a cathode and anode connected in shunt to said resistor and with a grid for controlling the transmission of current between said cathode and anode, and means comprising a pick-up device connected between said cathode and grid for controlling the conductivity of said device in accordance with variation in said electrical condition. I

3. The combination of an electric machine comprising load and field circuits, field control means connected in said field circuit, an electron discharge device comprising a grid interposed between a cathode and an anode connected to said field control means, and means connected between said cathode and grid for controlling the conductivity of said device in accordance with variation in an electrical condition of said load circuit.

a. The combination of an electric machine comprising load and field circuits, a resistor connected in said field circuit, an electron discharge device comprising a grid interposed between a cathode and an anode connected to said resistor, and avoltage responsive device connected between said cathode and grid for controlling the conductivity of said device in accordance with variation in the voltage of said load circuit.

5. The combination of'a load circuit. a plurality of devices for controlling an electrical condition of said circuit, an electron discharge device comprising grids interposed between a cathode connected to the juncture between said control devices and anodes connected to the terminals of said control devices, and means connected between said cathode and said grids for causing current to be transmltted through one of said devlces in response to variation of said condition in one direction and for causing current to be transmitted through the other 0t said devices in response to variation of said condition in the opposite direction.

6. The combination of an electric machine comprising field and load circuits, a plurality of control devices connected in said field circuit, an electron discharge device comprising grids interposed between a cathode connected to said field circuit at a. juncture between said control devices and anodes connected to the terminals of said control devices, and a voltage responsive device interconnecting said cathode and grids with said load circuit for regulating the potentials of said grids in response to variation in the voltage of said load circuit.

7. The combination of a load circuit, means for controlling the voltage of said circuit, a vapor electric device comprising a cathode and an anode connected to the terminals of said control means and a control electrode for controlling the transmission of current between its cathode and anode, and a pick-up device connected between sal load circuit and grid for varying the potential of said grid in response to change in the potential of said load circuit.

In witness whereof, I have hereuntoset my hand this 6th day of January, 1926.

ALBERT W.- "L- 

